lib: Add __fls() (Find Last Set)

Implement __fls() as an alias for log2(), and remove the duplicate
definitions in commonlib/storage/sdhci.c.

Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Change-Id: Ib458abfec7e03b2979569a8440a6e69b0285ac32
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59738
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
This commit is contained in:
Jianjun Wang 2021-11-30 10:51:53 +08:00 committed by Hung-Te Lin
parent 5588f34a35
commit 8bb59ca2fa
4 changed files with 19 additions and 32 deletions

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@ -457,6 +457,8 @@ static inline int clz(u32 x)
static inline int log2(u32 x) { return (int)sizeof(x) * 8 - clz(x) - 1; }
/* Find First Set: __ffs(0xf) == 0, __ffs(0) == -1, __ffs(1 << 31) == 31 */
static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); }
/* Find Last Set: __fls(1) == 0, __fls(5) == 2, __fls(1 << 31) == 31 */
static inline int __fls(u32 x) { return log2(x); }
static inline int popcnt64(u64 x) { return __builtin_popcountll(x); }
static inline int clz64(u64 x)
@ -466,6 +468,7 @@ static inline int clz64(u64 x)
static inline int log2_64(u64 x) { return sizeof(x) * 8 - clz64(x) - 1; }
static inline int __ffs64(u64 x) { return log2_64(x & (u64)(-(s64)x)); }
static inline int __fls64(u64 x) { return log2_64(x); }
/** @} */
/**

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@ -6,14 +6,15 @@
#include "bouncebuf.h"
#include <commonlib/sd_mmc_ctrlr.h>
#include <commonlib/sdhci.h>
#include <commonlib/stdlib.h>
#include <commonlib/storage.h>
#include <delay.h>
#include <endian.h>
#include <lib.h>
#include "sdhci.h"
#include "sd_mmc.h"
#include "storage.h"
#include <timer.h>
#include <commonlib/stdlib.h>
#define DMA_AVAILABLE ((CONFIG(SDHCI_ADMA_IN_BOOTBLOCK) && ENV_BOOTBLOCK) \
|| (CONFIG(SDHCI_ADMA_IN_VERSTAGE) && ENV_SEPARATE_VERSTAGE) \
@ -411,36 +412,6 @@ static int sdhci_set_clock(struct sdhci_ctrlr *sdhci_ctrlr, unsigned int clock)
return 0;
}
/* Find leftmost set bit in a 32 bit integer */
static int fls(u32 x)
{
int r = 32;
if (!x)
return 0;
if (!(x & 0xffff0000u)) {
x <<= 16;
r -= 16;
}
if (!(x & 0xff000000u)) {
x <<= 8;
r -= 8;
}
if (!(x & 0xf0000000u)) {
x <<= 4;
r -= 4;
}
if (!(x & 0xc0000000u)) {
x <<= 2;
r -= 2;
}
if (!(x & 0x80000000u)) {
x <<= 1;
r -= 1;
}
return r;
}
static void sdhci_set_power(struct sdhci_ctrlr *sdhci_ctrlr,
unsigned short power)
{
@ -718,7 +689,7 @@ static int sdhci_init(struct sdhci_ctrlr *sdhci_ctrlr)
if (rv)
return rv; /* The error has been already reported */
sdhci_set_power(sdhci_ctrlr, fls(ctrlr->voltages) - 1);
sdhci_set_power(sdhci_ctrlr, __fls(ctrlr->voltages));
if (ctrlr->caps & DRVR_CAP_NO_CD) {
unsigned int status;

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@ -53,6 +53,8 @@ static inline int clz(u32 x) { return x ? __builtin_clz(x) : sizeof(x) * 8; }
static inline int log2(u32 x) { return sizeof(x) * 8 - clz(x) - 1; }
/* Find First Set: __ffs(1) == 0, __ffs(0) == -1, __ffs(1<<31) == 31 */
static inline int __ffs(u32 x) { return log2(x & (u32)(-(s32)x)); }
/* Find Last Set: __fls(1) == 0, __fls(5) == 2, __fls(1 << 31) == 31 */
static inline int __fls(u32 x) { return log2(x); }
/* Integer binary logarithm (rounding up): log2_ceil(0) == -1, log2_ceil(5) == 3 */
static inline int log2_ceil(u32 x) { return (x == 0) ? -1 : log2(x - 1) + 1; }
@ -61,5 +63,6 @@ static inline int popcnt64(u64 x) { return __builtin_popcountll(x); }
static inline int clz64(u64 x) { return x ? __builtin_clzll(x) : sizeof(x) * 8; }
static inline int log2_64(u64 x) { return sizeof(x) * 8 - clz64(x) - 1; }
static inline int __ffs64(u64 x) { return log2_64(x & (u64)(-(s64)x)); }
static inline int __fls64(u64 x) { return log2_64(x); }
#endif /* __LIB_H__ */

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@ -37,6 +37,15 @@ void test_ffs(void **state)
assert_int_equal(__ffs(0xffffffff), 0);
}
void test_fls(void **state)
{
assert_int_equal(__fls(0x0), -1);
assert_int_equal(__fls(0x1), 0);
assert_int_equal(__fls(0x5), 2);
assert_int_equal(__fls(0x80000000), 31);
assert_int_equal(__fls(0xffffffff), 31);
}
void test_log2_ceil(void **state)
{
assert_int_equal(log2_ceil(0x0), -1);
@ -53,6 +62,7 @@ int main(void)
cmocka_unit_test(test_clz),
cmocka_unit_test(test_log2),
cmocka_unit_test(test_ffs),
cmocka_unit_test(test_fls),
cmocka_unit_test(test_log2_ceil),
};